Orientation Agnostic Electrical Connector

ABSTRACT

The invention teaches how to establish 1 to 1 connection between a first group of n electrical signals to a second group of n electrical signals. A first connector half with a first group of n1 contacts equally spaced around a circle and a second connector half with a second group n2 connectors, also equally spaced around a circle, with n1−1=n2≥n. The angular extent of the individual contacts from the first group is e1, and that from the second group is e2. The angular extent of the gap between individual contacts from the second group is g2. Following relationship must be satisfied: e1&lt;g2 and e2&gt;(360/n1−e1). 
     A switch interconnect means for connecting arbitrarily selected n contacts out of a first group of n1 contacts where (n1−1) n to n signals from a first group of n signals. The minimum number of signals required for doing this is n+(n1−n)*n. A single pole switch is connected from each of the n signals from the first group to each of the n arbitrarily selected contacts from the first group of n1 contacts. Each of the remaining n1−n contacts from first group, is connected to one end of a group of n switches. The other end of each switch from this group of switches is connected to each of the n signals from second group.

This application is a Continuation of U.S. application Ser. No.15/844,552, filed on Dec. 17, 2017. These and all other referencedextrinsic materials are incorporated herein by reference in theirentirety. Where a definition or use of a term in a reference that isincorporated by reference is inconsistent or contrary to the definitionof that term provided herein, the definition of that term providedherein is deemed to be controlling.

FIELD OF THE INVENTION AND PRIOR ART RELATED TO THE INVENTION

The field of invention is electrical connectors. Specifically, theconnectors that tolerate rotational misalignments. The basic techniquesprevalent in the prior for transferring electrical energy across aswivel joint can be summarized into three categories: (i) a flexible,twistable or bendable cable that connects across the swivel andcompensate for the swivel's motion. At one or both ends of the cable isa traditional detachable connector, (ii) an axial or radial slip ring orvariant, (iii) integrating a rotary switch into the connector where awiper can rotate to meet discrete contacts disposed along a circle. Asearch of prior art in class CPC/H01R35/00 reveals several examples ofall of the three categories. Each of these techniques have certainlimitations as described below.

-   (i) Flexible Wire Type: U.S. Pat. Nos. 9,673,585; 9,325,134;    9,698,551, 9,160,100 disclose a connector which takes with it a    cable that twists around to compensate for the swivel motion.    Here, (a) the actual pieces across which the connector is split,    still require precise alignment during mating, and this type of    designs cannot be used if the rotational misalignment is across the    two halves of the connector, (b) he twisting cable limits the life    of the connector, (c) the swivel has to be large enough to be able    to accommodate the cable, (d) being a twisting cable, it is required    to be thin. Consequently, it's a challenge to apply such technique    to large current connector.-   (ii) Slip Ring Type: U.S. Pat. Nos. 8,905,764 and 9,028,261 disclose    traditional slip rings. The former is an axial and the latter is a    radial slip ring design, both of which assign dedicated conductors    for each signal. As a result, these designs need significantly more    axial or radial space as the case may be. Furthermore, the slip    rings and contacts are assembled permanently or quasi permanently as    opposed to being on separable halves of mating connector. Thus, the    final mating pin-and socket, i.e. the detachable parts of the    connector still need precise alignment with respect to each other.    Additional examples include U.S. Pat. No. 9,130,330 which discloses    a radial liquid contact slip ring.-   (iii) Rotary Switch Type: U.S. Pat. Nos. 9,502,847, 8,597,059    disclose a connector that is a combination of a rotary switch and a    plug. This can connect electricity only in few discrete angular    positions. Due to the fundamental limitation of break-before make    requirement, the connector cannot transfer energy when connector    orientation does not match the few discrete functional positions.

As described above, each of the techniques described in prior are haveshortcomings that limit their use for a high current, compact connectorthat can tolerate rotational misalignment. With the re-birth of electricvehicles (EVs), their charging system and in particular automatic orrobotic charging system is fast becoming key enabling technology. At thecore of such as charging system is a high current capacity connector,that is compact and can tolerate several degrees of misalignment. Theconnector's tolerance to rotational misalignment allows for robot tohave one less degree of freedom, thus reducing complexity of endeffector as well as the overall robot. The chassis of an EV or for thatmatter any vehicle is floating on its suspension springs andconsequently the charge port attached to the chassis of a parked EV canstill move several inches when for example, the drive closes the door,or puts groceries in the car. A robot plugging into the charge port orthe charge port itself could easily get damaged when the EV chassismoves. Connector disclosed in this invention allows for the at least oneof the necessary degrees of freedom, while safely delivering largecharging currents.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1: Connector agnostic to angular orientation: Isometric view,disengaged position.

FIG. 2: Connector agnostic to angular orientation: Isometric view,disengaged position.

FIG. 3 Connector agnostic to angular orientation: Isometric view,engaged and aligned position.

FIG. 4 Connector agnostic to angular orientation: Isometric view,engaged and miss-aligned position.

FIG. 5 Contact topology for a connector agnostic to angular orientationand overall system connections: Top view.

FIG. 6 Contact topology for a connector agnostic to angular orientationand overall system connections: Top view.

FIG. 7 Contact topology for a connector agnostic to angular orientationand overall system connections: Top view.

FIG. 8 Contact topology for a connector agnostic to angular orientationand overall system connections: Top view.

FIG. 9 Contact topology for a connector agnostic to angular orientationand system connections optimized to minimize switch count: Top view.

FIG. 10 Contact topology for a connector agnostic to angular orientationand system connections optimized to minimize switch count: Top view.

FIG. 11 Contact topology for a connector agnostic to angular orientationand system connections optimized to minimize switch count+hardware todetect the contact disposition.

FIG. 12 Contact topology for a connector agnostic to angular orientationand system connections optimized to minimize switch count+hardware todetect the contact disposition.

FIG. 13 Contact topology for a connector agnostic to angular orientationand system connections optimized to minimize switch count+hardware todetect the contact disposition.

FIG. 14 Contact topology for a connector agnostic to angular orientationand system connections optimized to minimize switch count+hardware todetect the contact disposition, with one less switch.

DETAILED DESCRIPTION OF THE INVENTION

Electrical power connectors have two halves, each carrying a group ofconnectors. These connector halves are brought together to mate witheach other in a particular relative orientation. Frequently, theconnectors have mechanical guides on one or both halves to guide themating process into correct orientation such that each of the contactsfrom the first half mates with its matching counterpart from the secondhalf. This invention teaches a contactor design that eliminates need forprecise angular orientation of two halves of a power connector.

The Arrangement:

One of the embodiments of this invention is shown in FIG. 1 and FIG. 2.It comprises of two halves 10 and 20. Where 10 carries a group ofcontactors 6, and 20 carries a group of connectors 5. For the purpose ofvisualization two marking notches 11 and 21 are inscribed on the lateralsurfaces of 10 and 20 respectively. It should be noted that 11 and 21 donot play any role in the functioning of the connector. These two halves10 and 20 mate as shown in FIG. 3 and FIG. 4. Here, FIG. 3 shows thebasic configuration of the two halves 10 and 20 after mating.Additionally, as shown in FIG. 4, this innovation teaches contactordesign that allows 10 and 20 to mate in any angular orientation 30. If arobot were to bring the two halves 10 and 20 together, this innovationallows the robot to not need a rotational actuator to align the twohalves in direction 30.

FIG. 5 shows the top view of one embodiment of the invention. Thisembodiment is meant to connect n=2 electrical signals marked as S1 andS2 with a second group of electrical signals marked as L1 and L2. Justas an example, S1 and S2 are shown to emerge from an electricity source1, and L1 and L2 are terminating into an electrical load 7. However itis not necessary for the first and send group of electrical signals tobe source and load respectively. FIG. 5 shows the first set of n1 countof contacts 6A, 6B and 6C mounted on the first half 10, with n1=3. Asseen in FIG. 5, some of the contacts 6A, 6B, and 6C connect withcontacts from the second group of n2 count of contacts 5A and 5B withn2=2, mounted on second half 20 (not shown in FIG. 5). It should benoted that n2=n1−1≥n. The first group of contacts 6A, 6B, and 6C areevenly spaced around a circle with each contact having an angular extentof e1. The contacts 5A and 5B are also evenly spaced around a circlewith the gaps between them having an angular extend of g2 and thecontacts themselves having an angular extent of e2. It's clear that e2and g2 are not independent, but are related by: 360=n2×(e2+g2). Thegeometry is arranged such that e1<g2 and that e2>(360/n1−e1). Thisensures that any one of 6A, 6B or 6C never bridges the gap between 5Aand 5B, thus never short circuiting 5A with 5B. Also, there will be atleast one contact from the first group that will connect with each ofthe contacts from the second group.

Each of the first group of contacts 6A, 6B and 6C is connected to firstterminal of a pair of switches. Specifically, 6A is connected to one endof each of the two switches from the first pair 4A and 4B, 6B isconnected to one end of each of the two switches from the second pair 2Aand 2B and 6C is connected to one end of each of the two switches fromthe third pair 3A and 3B. The remaining end of first switch from each ofthe first, second and third pairs is connected to S1. The remaining endof second switch from each of the first, second and third pairs isconnected to S1 (see FIG. 5). When 2A, 2B, 3A, 3B, 4A and 4B arecorrectly configures, either S1 or S2 can be connected to any one thecontacts 6A, 6B or 6C. When n=n2, as is the case in this embodiment,each of the contacts from the second group is connected directly to aunique signal from the second group. For example in this embodiment, 5Ais connected to L2 and 5B is connected to L1.

Operation: FIG. 6, FIG. 7 and FIG. 8 show the two connector halves atdifferent orientations with respect to each other. Stating from thepicture in FIG. 6; FIG. 7 and FIG. 8 show how the contacts progressivelydispose themselves when first contactor half 10 rotates counterclockwisewith respect to second contactor half 20. As seen in FIG. 7, 6A—whichwas previously disconnected, comes in contact with 5A, much before 6Bdeparts away from 5A. By the time 6B fully departs from 5A as seen inFIG. 8, 6A has fully established contact with 5A. Thus, at anyrotational misalignment, the minimum required number of conduction pathsare always available. All that is needed is for the control circuitry tofigure out the rotational position and configure switches 2A, 2B, 3A,3B, 4A and 4B appropriately as shown in FIG. 6, FIG. 7 and FIG. 8. Thisconfiguration can be either set manually or automatically by amicroprocessor.

Advantages:

The invention disclosed here uses a single ring for establishing allconduction paths. As a result, the mating surface and contacts haveseveral desirable features: (i) The individual contacts can be madelarger by taking advantage of the space saving design of single ring ofcontacts. This is particularly important for handling very high currentsas the larger contacts not only allow for good sized contact surface anda large conductive body, but are also capable for dissipating any heatgenerated. (ii) This invention allows mating connector halves totolerate rotational misalignment. This is important to be able to reducethe number of actuators required if the two mating halves are broughttogether mechanically.

Refinement1:

The embodiment in FIG. 5 uses six switches (n*n1). This arrangementallows connecting one particular signal from the first group (S1 or S2)to any one of the signals from second group (L1 or L2). In other words,the arrangement in FIG. 5 allows S1 to be connected to L1 or L2 withoutany constraint. Likewise, S2 can also be connected either to L1 or L2.Actual connection configuration can be chosen by the end user. However,if this degree of freedom is not required, but the only requirement isto connect S1 to one of the L1 and L2, and S2 to the other, then thenumber of switches can be reduced to 4 which is (n1−n)*n+n, which isalways less than n*n1). The specific arrangement for n=2 and n1=3 isshown in FIG. 9, which comprises of switches 8A, 8B-1, 8B-2 and 8C. TheFIG. 9 shows the switches in open state and the FIG. 10 shows theswitches in correct configuration to connect S1 and S2 to 6C and 6Brespectively, which in turn connect with 5B and 5A respectively, whichin turn connect to L1 and L2 respectively. Note that with the reducednumber of switches, S1 to L1 and S2 to L2 is the only possibleconnection available in the configuration in FIG. 10. Typically, this isnot a concern if the load or source is polarity agnostic, e.g. as is thecase when 1 is an AC source and/or 7 is a resistive load.

Refinement2:

In order to configure the group of switches 2A, 2B, 3A, 3B, 4A, 4B orthe group of switches 8A, 8B-1, 8B-2, 8C; one needs to know whichcontacts 6A, 6B and 6C from the first group have connected with whichparticular contacts 5A or 5B from the second group. One approach is theuse an encoder or an equivalent orientation sensor to measure relativeorientation between 10 and 20. However, this could be expensive. Insteadthis invention teaches a novel approach of adding two switches 9A and 9Bto signal paths for L1 and L2 as shown in FIG. 11. By using a specificsequence of switch configurations and continuity checks, amicroprocessor or a human being can figure out how to configure theswitches 2A, 2B, 3A, 3B, 4A, 4B or 8A, 8B-1, 8B-2, 8C. These steps arelisted below:

-   Step 1: Disconnect 6A, 6B and 6C from S1 as well as S2. This means    opening all of the switches 2A, 2B, 3A, 3B, 4A, 4B or 8A, 8B-1,    8B-2, 8C. Also disconnect 5A and 5B from load or from each other.    This means open 9A and 9B. See FIG. 11. Please note that the switch    9A is optional if (i) load 7 is capable of withstanding the small    voltage used during the continuity checks used during this procedure    and (ii) offers a low resistance that is detectable by continuity    checks used during this procedure and in that case circuit of FIG.    11 can be simplified to circuit of FIG. 14-   Step 2: Perform pairwise continuity check on 6A, 6B and 6C. The    outcomes are all contacts are open, or two of them show short    circuit. This represents the orientation shown in FIG. 7, where 6A    and 6B are electrically connected by 5A.-   Step 3: Close the switch 9A. See FIG. 12.-   Step 4: Perform pairwise continuity check on 6A, 6B and 6C. The    outcomes are:    -   i. all contacts short circuited to each other (when 10 and 20        are oriented as shown in FIG. 7 i.e. when 6A and 6B are shorted        through 5A and 6C is shorted to 5A through the pathway:        6C->5B->9A->5A->{6A and 6B}).    -   ii. one pair is short circuited (when 10 and 20 are oriented as        shown in FIG. 6 or FIG. 8). The short circuit is through 9A        only.-   Step 5: Open switch 9A. Close switch 9B. See FIG. 13.-   Step 6: Combining the results of Step 2 and Step 4, one can    understand which of the 6A, 6B or 6C are connected to 5A and 5B.    Configure switches 2A, 2B, 3A, 3B, 4A, 4B or switch 8A, 8B-1, 8B-2,    8C appropriately.

Application:

One of the important application of this technology is in the field ofrobotic hands-free charging of electric vehicles (EVs). In thisapplication, a robot end effector would be installed with one half of anEV charging connector, and the other half would be installed on theelectric vehicle. When the EV is to be charged, the robot would move itsend effector and the attached connector half to bring it next to theconnector half mounted on the EV. If this connector is to be designed asdescribed in this invention, the Robot would not need to angularly alignthe two connector halves. This way, the robot end effector complexitycan be reduced.

Another application is in the field of slip rings. In the traditionaldesign of slip rings, each individual connection being transmittedacross has its own dedicated ring. With the principle described in inthis invention, multiple connections can be integrated into single slipring that is peripherally segmented. This does add the complication ofextra switching, as well as continuous monitoring of slip ringconfiguration. However, it allows for a significantly smaller slip ringdesign to be realized.

A third application is in the field of aerial drone recharging stations.The drone can simple land on the charging pad and not worry about therotational alignment. The drone's landing gear will be fashioned as aring, forming one half of the charging connector, and the charging padsurface will have appropriate mating connector embedded in it.

SUMMARY

The invention teaches how to establish 1 to 1 connection between a firstgroup of n electrical signals to a second group of n electrical signals.A first connector half with a first group of n1 contacts equally spacedaround a circle and a second connector half with a second group n2connectors, also equally spaced around a circle, with n1−1=n2≥n. Theangular extent of the individual contacts from the first group is e1,and that from the second group is e2. The angular extent of the gapbetween individual contacts from the second group is g2. Followingrelationship must be satisfied: e1<g2 and e2>(360/n1−e1).

A switch interconnect means for connecting arbitrarily selected ncontacts out of a first group of n1 contacts where (n1−1) n to n signalsfrom a first group of n signals. The minimum number of signals requiredfor doing this is n+(n1−n)*n. A single pole switch is connected fromeach of the n signals from the first group to each of the n arbitrarilyselected contacts from the first group of n1 contacts. Each of theremaining n1−n contacts from first group, is connected to one end of agroup of n switches. The other end of each switch from this group ofswitches is connected to each of the n signals from second group.

What is presented in this patent application are only few representativeembodiments of the core innovation. There are countless situations wherethis innovation can be applied. Any variant embodiments of thisinnovation are anticipated by this disclosure and hence are to beconsidered as part of this patent.

What is claimed is:
 1. A method of establishing an electrical powerconnection across potentially misaligned a first and a second powerconnector bodies, the first connector body carries a first set ofcontactors and the second connector body carries a second set ofcontactors, comprising: a. providing first circuitry that identifies atleast first and second electrically mating pairs that are electricallyisolated from each other, from among the first and second sets ofcontactors; and b. providing second circuitry that establishes the powerconnection using the at least first and second electrically matingpairs.
 2. The method of claim 1, wherein the first set of contactors hasat least two contactor members, and the second set of contactors has atleast three contactor members.
 3. The method of claim 1, wherein thefirst set of contactors has n contactor members, and the second set ofcontactors has at least n+1 members.
 4. The method of claim 1, whereinthe first circuit identifies a third electrically mating pair that iselectrically isolated from the first and the second electrically matingpairs, from among the first and second sets of contactors, and whereinthe second circuitry establishes a power connection using the thirdelectrically mating pair.
 5. The method of claim 4, wherein the firstcircuit identifies a fourth electrically mating pair that iselectrically isolated from the first, the second and the thirdelectrically mating pairs, from among the first and second sets ofcontactors, and wherein the second circuitry establishes a powerconnection using the fourth electrically mating pair.
 6. The method ofclaim 1, wherein the first and the second connector bodies are shaped tomeet along a planer interface.
 7. The method of claim 1, furthercomprising utilizing the power connection to charge an electric vehicle.